Hereditary amyloidosis: description of a new American kindred with late onset cardiomyopathy. Appalachian amyloid.

A family with hereditary amyloidosis characterized by peripheral neuropathy and cardiomyopathy is described. Lack of eye involvement sets their disease apart from the Indiana/Swiss familial amyloidotic polyneuropathy type II. The disease is of late onset; affected members die of cardiomyopathy after age 60. The late onset and lack of clinically significant neuropathy in several family members has led to misdiagnosis of the cardiomyopathy. Immunohistochemistry using antiprealbumin antiserum showed staining of amyloid deposits in nerve and heart.